Pneumomediastinum
Free air within the mediastinum that can appear as streaky lucency around central chest structures
Pneumomediastinum means free air is present in the mediastinum and may appear as linear lucency outlining the heart, great vessels, or central airways on X-ray.
Pneumomediastinum means air has escaped into the central chest compartment between the lungs. It can happen from alveolar rupture, trauma, severe coughing, vomiting, asthma flare, or injury to the airways or esophagus.
Representative X-ray
Representative annotated X-ray not available for this topic yet.
We only show a representative image when there is a clean corresponding source in the current reference set.
What it is
- This is a radiographic finding of mediastinal free air
- It can be spontaneous or secondary to trauma, barotrauma, infection, airway injury, or esophageal perforation
How it appears on chest X-ray
- Chest X-ray may show lucent streaks or outlines around the cardiac silhouette, aortic arch, trachea, or mediastinal contours
- Air may extend into the neck or coexist with subcutaneous emphysema
What radiologists look for
- Radiologists assess whether the air is confined to the mediastinum, whether there is also pneumothorax or subcutaneous emphysema, and whether the pattern raises concern for airway or esophageal injury
How X-ray helps
- Chest X-ray can reveal the presence and distribution of mediastinal air, but CT may be needed to clarify subtle cases or identify the source
Common causes
- Causes include spontaneous alveolar rupture, asthma, forceful coughing, vomiting, trauma, mechanical ventilation, infection, airway injury, and esophageal perforation
Symptoms / associated symptoms
- Symptoms can include chest pain, shortness of breath, neck swelling, voice change, pain with swallowing, or a crunching sensation with heartbeat in some cases
Risk factors
- Risk factors include asthma, inhalational injury, intense Valsalva, trauma, vomiting, barotrauma, and recent procedures involving the airway or esophagus
Why it can matter clinically
- Complications depend on the cause and can include pneumothorax, progressive air leak, mediastinal compression, or life-threatening esophageal injury
When to seek medical care
- Chest pain, shortness of breath, trauma, neck swelling, or severe vomiting with chest symptoms should be assessed promptly
Evaluation and diagnosis
- Evaluation depends on the suspected cause and may include CT chest, airway assessment, esophageal workup, oxygen support, and monitoring for associated complications
Treatment approaches
- Treatment ranges from observation and oxygen support for uncomplicated cases to urgent workup and intervention when trauma, perforation, or major air leak is suspected
Medication classes clinicians may use
There is no single medication that treats pneumomediastinum itself; management depends on the underlying cause and severity.
Treatment modalities commonly paired with medication decisions
- Observation in selected cases
- Supplemental oxygen
- Treatment of underlying cause
- Urgent trauma or surgical evaluation when indicated
Analgesics
Used to control pain while the underlying cause is assessed and treated.
- acetaminophen
- ibuprofen
FAQ
Is pneumomediastinum the same as pneumothorax?
No. Pneumomediastinum is air in the mediastinum, while pneumothorax is air in the pleural space around the lung.
Can pneumomediastinum go away on its own?
Sometimes yes, especially in mild spontaneous cases, but the cause still matters because some causes need urgent treatment.